/*
 * Copyright 2005-2007 Russ Cox, Massachusetts Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#define setcontext(u) _setmcontext(&(u)->mc)
#define getcontext(u) _getmcontext(&(u)->mc)
typedef struct mcontext mcontext_t;
typedef struct ucontext ucontext_t;

struct mcontext {
	ulong pc; /* lr */
	ulong cr; /* mfcr */
	ulong ctr; /* mfcr */
	ulong xer; /* mfcr */
	ulong sp; /* callee saved: r1 */
	ulong toc; /* callee saved: r2 */
	ulong r3; /* first arg to function, return register: r3 */
	ulong gpr[19]; /* callee saved: r13-r31 */
};

struct ucontext {
	struct {
		void *ss_sp;
		uint ss_size;
	} uc_stack;
	sigset_t uc_sigmask;
	mcontext_t mc;
};

void makecontext(ucontext_t*, void(*)(void), int, ...);
int swapcontext(ucontext_t*, const ucontext_t*);
int _getmcontext(mcontext_t*);
void _setmcontext(const mcontext_t*);
